Hurt after being denied the BJP ticket to contest from Barmer, the Bharatiya Janata Party (BJP) veteran also accused party president Rajnath Singh and Rajasthan Chief Minister Vasundhara Raje of betraying the BJP's ideology and turning it into another Congress.

"There is no effort to take everyone along. This is a dangerous route, better if they tread with caution," he added.

Jaswant Singh did not say anything else about Modi but was unsparing of Rajnath Singh, a Modi confidant, and Vasundhara Raje.

"They have betrayed me," he earlier told a gathering of his supporters, saying it was he who had recommended Rajnath Singh and Vasundhara Raje for the posts they now hold.

And sounding emotional, Jaswant Singh said he felt "extremely relieved" Monday and sought the support of the people of Barmer, his home turf, saying it was a question of their honour too.

"The BJP has become like the Congress, indulging in vote bank politics. It has abandoned its principles and ideology."

In an obvious reference to Congress leaders now joining the BJP, Jaswant Singh said the recent entrants had no connection with the BJP ideology.

The former external affairs minister dared the BJP to remove him. "I will not say goodbye till the party says goodbye."

A long-time associate of BJP stars Atal Bihari Vajpayee and L.K. Advani, Jaswant Singh said returning to the BJP in 2010 after his expulsion earlier was a mistake.

"The way I was expelled after the BJP Shimla convention, even a 'chaprasi' (peon) isn't expelled like that," Jaswant Singh told the rally.

"Perhaps it was an emotional weakness that I joined the BJP again though all my relatives and friends had sought to dissuade me."

Jaswant Singh, elected to the Lok Sabha in 2009 from Darjeeling in West Bengal, wanted to contest from the Lok Sabha election from Barmer this time.

But the ticket was given to former Congress leader Sonaram Choudhary, who recently joined the BJP.

Talking to a television news channel, Jaswant Singh challenged Choudhary's ability to win, saying he (Choudhary) lost the recent assembly elections to a BJP candidate.

Faced with an embarrassing situation it did not bargain for ahead of the Lok Sabha battle, the BJP spoke in contrary voices.

"We cannot comment on his decision. As far as the party is concerned, he is a respected leader and we still respect him," BJP's Mukhtar Abbas Naqvi said in New Delhi.

But BJP's M. Venkaiah Naidu launched a mild attack on him.

"The party has given him lot of respect. He was made leader of the opposition in the Rajya Sabha, he was a cabinet minister," said Naidu.

"If he was denied a ticket for some political reason, going against the party is not good."

The Congress used the opportunity to attack the BJP.

"It is against our culture and tradition to disrespect the elders. But when you have an individual for whom it is just I-me-myself, it is authoritarianism of the worst kind," party leader Anand Sharma said in a clear attack on Modi.

Law Minister Kapil Sibal added: "people who have served the BJP for three decades, they are not being given importance... Yes, he is feeling betrayed. Soon others will feel betrayed as well."